I've got a pair. IMO they are nice, but I doubt that they show the same output gains as the SE style lamps. I say this because the SE luminarcs have almost no interruption in the light reflection, whereas with the DE luminarcs the lamp sockets seem to get in the way somewhat.
That said, they DO pour out the light and spread it very nicely over the coverage area. IMO much more balanced spread than other DE reflectors I've seen or used, less hot spot right in the center, much more light to the edges. I'd reccomend them for a 24" wide tank, but probably not for a 12" or 18" wide tank.
One other note, it is a bit of a PITA to change bulbs and or remove the glass sheilds for cleaning. You need to remove a whole side of the outer reflector shroud to get the sheild out, and lining the screw holes back up for reassemble is tricky.
Overall, I'd say they are very nice for the right set up, but not every set up.